The term “vanin inhibitor” is preferably defined herein as a compound which, in vitro and/or in vivo: (i) inhibits the activity and/or expression of Vanin-1; and/or (ii) blocks processing of pantetheine into cysteamine and pantothenic acid; and/or (iii) blocks intracellular synthesis of cysteamine and/or of cystamine, the oxidized form of cysteamine. Inhibition and blocking may be total or partial.
Vanin-1 and Vanin-3 are preferentially expressed by epithelial and myeloid cells, respectively (Martin, 2001). In human and drosophila, this enzyme is encoded by 3 genes (VNN-1, VNN-2, VNN-3). In mouse and human, Vanin-1 and VNN1, respectively, are GPI-anchored to cell membranes and are highly expressed at the brush border of various epithelial cells, including intestinal enterocytes, kidney tubular cells, hepatocytes, pancreatic acinar cells, and thymic medullary epithelial cells (Galland, 1998; Aurrand-Lions, 1996; Pitari, 2000; Martin, 2001). In drosophila, 4 genes homologous to the mammalian Vanin sequences are identified and preliminary studies show that drosophila has a pantetheinase activity (Granjeaud et al., 1999).
Vanin-1 deficient mice develop normally but have no detectable free cytsteamine/cystamine in kidney and liver, in spite of the presence of Vanin-3 (Pitari, 2000).
Inactivation of the Vanin-1 gene prevents acute and chronic inflammation since in both cases intestinal injury was moderate in Vanin-1 deficient mice, as compared to controls. The protection was associated with reduced expression of inflammatory molecules, myeloid cell recruitment and mucosal damage in the intestine. Furthermore, glutathione synthesis and storage were increased in liver and intestine (US 2004/0247524). These events were further shown to be associated with the lack of free cysteamine/cystamine, which is undetectable in Vanin-1 deficient mice, since cystamine given orally reversed the inflammatory phenotype. This reverting effect was correlated with inhibition of glutathione synthesis in vivo. Thus, the compounds of formula I, which show pronounced activity as vanin inhibitors, are useful for the treatment of inflammatory disorders.
As used herein, “inflammatory disorder” denotes a condition of sustained or chronic inflammation that occurs when tissues are injured by viruses, bacteria, trauma, chemicals, heat, cold or any other harmful stimulus. Preferably, an inflammatory disorder according to the invention is a gastrointestinal inflammatory disorder that may be selected from the group consisting of an inflammatory bowel disease (IBD) such as Irritable Bowel Syndrome (IBS), ulcerative colitis and Crohn's disease, an ulcer resulting from administration of a non-steroidal anti-inflammatory drug, such as a peptic ulcer (i.e., a sore that forms in the lining of the stomach or the duodenum), and an inflammatory disorder associated with an infection with the Schistosoma mansoni parasite.
The term “treating” or “treatment” is meant the prophylactic or curative treatment of a disorder, i.e., reversing, alleviating, inhibiting the progress of, or preventing the disorder or condition to which such term applies, or one or more symptoms of such disorder or condition. The treatment may be associated with another pre-existing treatment in order to improve the efficacy of said pre-existing treatment.
Preferred embodiments of the present invention and preferred definitions used therein are described in the following:
Alkyl denotes a carbon chain having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms and most preferably 1 to 6 carbon atoms. Alkyl very preferably denotes methyl, furthermore ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl or tert-butyl, furthermore also pentyl, 1, 2 or 3 methylbutyl, 1,1-, 1,2- or 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, 1, 2, 3 or 4 methylpentyl, 1,1-, 1,2-, 1,3-, 2,2-, 2,3- or 3,3-dimethylbutyl, 1 or 2 ethylbutyl, 1 ethyl-1-methylpropyl, 1 ethyl-2-methylpropyl, or 1,1,2- or 1,2,2-trimethylpropyl
The group O-alkyl preferably denotes methoxy and ethoxy.
Ar preferably denotes phenyl or biphenyl, which may be unsubstituted or monosubstituted, disubstituted or trisubstituted by a substituent selected from a group mentioned under the definition of Ar.
Het preferably denotes a monocyclic or bicyclic, saturated, unsaturated or aromatic heterocyclic ring having 1 to 3 N, O or S atoms which may be unsubstituted or monosubstituted, disubstituted or trisubstituted by a substituent selected from a group mentioned under the definition of Het.
Het is more preferably a 6- to 14-membered ring system and denotes, notwithstanding further substitutions, for example, 2 or 3 furyl, 2 or 3 thienyl, 1, 2 or 3 pyrrolyl, 1, 2, 4 or 5 imidazolyl, 1, 3, 4 or 5 pyrazolyl, 2, 4 or 5 oxazolyl, 3, 4 or 5 isoxazolyl, 2, 4 or 5 thiazolyl, 3, 4 or 5 isothiazolyl, 2, 3 or 4-pyridyl, 2, 4, 5 or 6 pyrimidinyl, furthermore preferably 1,2,3-triazol-1, 4- or 5-yl, 1,2,4-triazol-1, 3- or 5 yl, 1 or 5 tetrazolyl, 1,2,3-oxadiazol-4- or 5-yl, 1,2,4-oxadiazol-3- or 5-yl, 1,3,4-thiadiazol-2- or 5-yl, 1,2,4-thiadiazol-3- or 5-yl, 1,2,3-thiadiazol-4- or 5 yl, 3 or 4 pyridazinyl, pyrazinyl, 1, 2, 3, 4, 5, 6 or 7 indolyl, indazolyl, 4 or 5 isoindolyl, 1, 2, 4 or 5-benzimidazolyl, 1, 3, 4, 5, 6 or 7 benzopyrazolyl, 2, 4, 5, 6 or 7-benzoxazolyl, 3, 4, 5, 6 or 7 benzisoxazolyl, 2, 4, 5, 6 or 7 benzothiazolyl, 2, 4, 5, 6 or 7 benzisothiazolyl, 4, 5, 6 or 7 benz-2,1,3-oxadiazolyl, 2, 3, 4, 5, 6, 7 or 8 quinolyl, 1, 3, 4, 5, 6, 7 or 8 isoquinolyl, 3, 4, 5, 6, 7 or 8 cinnolinyl, 2, 4, 5, 6, 7 or 8 quinazolinyl, 5 or 6 quinoxalinyl, 2, 3, 5, 6, 7 or 8 2H-benzo-1,4-oxazinyl, furthermore preferably 1,3-benzodioxol-5-yl, 1,4-benzodioxane-6-yl, 2,1,3-benzothiadiazol-4- or 5-yl or 2,1,3-benzoxadiazol-5-yl.
The heterocyclic radicals may also be partially or fully hydrogenated.
Het can thus also denote, for example, 2,3-dihydro-2, 3, 4- or 5-furyl, 2,5-dihydro-2, 3, 4- or 5 furyl, tetrahydro-2- or 3-furyl, 1,3-dioxolan-4-yl, tetrahydro-2- or 3-thienyl, 2,3-dihydro-1, 2, 3, 4- or 5-pyrrolyl, 2,5-dihydro-1, 2, 3, 4- or 5-pyrrolyl, 1, 2 or 3 pyrrolidinyl, tetrahydro-1, 2- or 4-imidazolyl, 2,3-dihydro-1, 2, 3, 4- or 5-pyrazolyl, tetrahydro-1, 3- or 4-pyrazolyl, 1,4-dihydro-1, 2, 3- or 4-pyridyl, 1,2,3,4-tetrahydro-1, 2, 3, 4, 5- or 6-pyridyl, 1, 2, 3 or 4 piperidinyl, 2, 3 or 4 morpholinyl, tetrahydro-2, 3- or 4-pyranyl, 1,4-dioxaneyl, 1,3-dioxane-2, 4- or 5-yl, hexahydro-1, 3- or 4-pyridazinyl, hexahydro-1, 2, 4- or 5-pyrimidinyl, 1, 2 or 3 piperazinyl, 1,2,3,4-tetrahydro-1, 2, 3, 4, 5, 6, 7- or 8-quinolyl, 1,2,3,4-tetrahydro-1, 2, 3, 4, 5, 6, 7- or 8-isoquinolyl, 2, 3, 5, 6, 7 or 8 3,4-dihydro-2H-benzo-1,4-oxazinyl, furthermore preferably 2,3-methylenedioxyphenyl, 3,4-methylenedioxyphenyl, 2,3-ethylenedioxyphenyl, 3,4-ethylenedioxyphenyl, 3,4-(difluoromethylenedioxy)phenyl, 2,3-dihydrobenzofuran-5- or 6 yl, 2,3-(2-oxomethylenedioxy)phenyl or 3,4-dihydro-2H-1,5-benzodioxepin-6- or 7-yl, furthermore preferably 2,3-dihydrobenzofuranyl or 2,3-dihydro-2-oxofuranyl.
Cyc preferably denotes cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl.
Above and below, all radicals and indices, such as T1, T2, W, Rw, Ra, Rb, Rc, Ar, Het, Hal and n, have the meaning indicated under formula (I), unless expressly stated otherwise.
Generally, compounds of formula I are the more preferred, the more preferred substituents they carry.
W preferably denotes a single bond CH2 or —CH═CH—.
Rw preferably denotes H, alkyl, (CH2)2Ar, such as phenyl, and in cases where T2-W is
also Hal, more preferably Cl and F.Ra is preferably H, benzyl, (CH2)2phenyl, (CH2)3phenyl or (CH2)2Ophenyl.Rb is preferably H.Rc is preferably H.N is preferably 1.
Compounds of Formula (I) wherein Rw denotes H, Hal, or a linear or branched alkyl are preferred.
Compounds of Formula (I) wherein Rw denotes one of the following groups are also preferred:
wherein ammonium ions have Hal or mesylate as a counter ion.
Moreover, compounds of formula I are preferred, wherein Rb and Rw, together with the nitrogen atom to which they are linked, form one of the following groups:

Very preferred embodiments of the present invention are compounds 1 to 84, which are identified below together with their respective activities:
IC50IC50VNN1cellExCHEMISTRY(μM)(μM) 15.37  220.50  39.251.27  42.011.19  53.313.20  65.790.67  70.831.49  81.683.54  90.040.03 100.030.025 110.030.073 120.09 130.46 140.050.09 150.050.14 168.32 170.030.02 183.35 190.030.05 203.03 2111.50 220.060.03 230.070.05 240.01<0.01 252.32 260.380.26 279.73 280.020.10 290.70 300.03 31<0.010.01 32<0.01<0.01 33<0.01<0.01 340.02 350.07 360.17 37 0.01 38<0.01 390.02<0.01 400.40 410.01 420.34 4312.60 440.05 450.02 46<0.01 470.02 480.11 4923.00 500.03 510.02 520.05 530.01 540.09 55<0.01 560.01 572.541.11 582.480.22 594.041.20 603.570.60 613.280.22 621.360.21 633.55 643.44 653.99 662.87 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84wherein ammonium ions have Hal or mesylate as a counter ion.Synthesis of Compounds of the Invention:
The following general methods and procedures described hereinafter in the examples may be used to prepare compounds of formula (I) and related formulae.
The compounds according to formula (I) may be prepared from readily available starting materials using the following general methods and procedures. If such starting materials are not commercially available they may be prepared by standard synthetic techniques. It will be appreciated that where typical or preferred experimental conditions (i.e., reaction temperatures, time, stoichiometry of reagents, solvents, etc.) are given, other experimental conditions can also be used unless otherwise stated. Generally, the compounds according to the general formula (I) may be obtained by several processes using both solution-phase and/or solid-phase chemistry protocols. Examples of synthetic pathways for the preparation of compounds according to the general formula (I) are described herebelow. Optimum reaction conditions may vary with particular reactants or solvents used, but such conditions can be determined by the person skilled in the art, using routine optimization procedures.
Below, all substituents, such as T1, T2, W, Rw, Rb, Rc, Ra or n, have the meaning indicated under the formula (I) unless expressly stated otherwise.
Depending on the nature of T1, T2, W, Rw, Rb, Rc, Ra or n, different synthetic strategies may be selected for the synthesis of compounds of formula (I). In general, the synthesis pathways for any individual compound of formula (I) will depend on the specific substituents of each molecule and upon the availability of intermediates; again, such factors being appreciated by those skilled in the art. For all the protection and deprotection methods, see Philip J. Kocienski, in “Protecting Groups”, Georg Thieme Verlag, Stuttgart, Germany, 1994, and Theodora W. Greene and Peter G. M. Wuts in “Protective Groups in Organic Synthesis”, Wiley Interscience, 31rd Edition, 1999.
Structures below are drawn for compounds of (R) stereochemistry starting from D-pantolactone of formula (VI). The same reactions and procedure can be followed to obtain (S) derivatives, starting from L-pantolactone.
As a representative example, the compounds according to formula (I) may be prepared following the synthetic pathways described in the general scheme 1. According to a preferred synthetic pathway, compounds of formula (Ia) may be prepared from the corresponding derivatives of formula (IIa) by an oxidation step followed by the cleavage of the acetonide protecting group where, preferably, W represents a single bond or a group —CH═CH— and Rw an alkyl group. Preferred conditions consist of the treatment of compounds of formula (IIa) with an oxidant such as, but not limited to, Dess-Martin periodinane in a solvent such as dry DCM at room temperature for few hours, such as 2 h, followed by treatment with preferably an 80% acetic acid solution in water at room temperature for several hours, such as 3 h. Compounds of formula (IIa) may be prepared from the corresponding derivatives of formula (IIb), wherein W and Rw are as above defined, but preferably representing an alkyl group and W representing a single bond or a group —CH═CH—, by reaction of magnesium bromide derivatives of formula (III) with compounds of formula (IIb) in a solvent such as dry THF at 0° C. for 1 h followed by 1 h at RT. Starting from the alcohol (IIc), compounds of formula (IIb) can be obtained using usual conditions for the oxidation of primary alcohol into aldehyde using Dess-Martin oxidation or Swern oxidation conditions. Preferred conditions consist of the treatment of compounds of formula (IIc) with Dess-Martin periodinane in a solvent such as DCM at 0° C. for few hours, such as 6 h. The corresponding alcohol derivatives can be obtained after protection of compounds of formula (IVa) into an acetonide group by treatment of compounds of formula (IVa) with acetone in the presence of an acid such as, but not limited to, para-toluene sulfonic acid and molecular sieves at room temperature for several days, such as 3 days. Compounds (IVa) may be prepared by the opening of a pantolactone of formula (VI) with amines of formula (Va). Preferred conditions consist of the treatment of compounds of formula (VI) with amines in the presence of a base such as triethylamine, in a suitable solvent such as dry EtOH at a temperature between 100° C. and 160° C.
Compounds of formula (Ib), where Rw is as described above, may be prepared from compounds of formula (IId) following conditions described above to convert compounds of formula (Ia) from compounds of formula (IIa) consisting of the oxidation of the secondary alcohol into a ketone followed by the acetonide deprotection. Compounds of formula (IId) can be obtained from compounds of formula (IIb) by treatment with classic reagents to run Horner-Wadsworth-Emmons reactions such as phosphonate derivatives of formula (VII). Preferred conditions consist of the treatment of phosphonate of formula (VII) with NaH in a suitable solvent such as dry THF at 0° C. for few minutes, such as 15 minutes, followed by the addition of compounds of formula (IIb) at 0° C. for 1 h, then at RT for another hour.

When T2 denotes a —CO—CH═CH— group such as represented in Scheme 2, where Rw is as defined above, compounds of general formula (Ic) may be prepared from compounds of formula (IIe) following conditions described above to convert compounds of formula (Ia) from compounds of formula (IIa) consisting of the oxidation of the secondary alcohol into a ketone followed by the acetonide deprotection. Compounds of formula (IIe) can be obtained from compounds of formula (IIf) by treatment with an allyl derivative of formula (VIII) where Rw is as above defined in the presence of a Grubbs catalyst. Preferred conditions consist of the treatment compounds of formula (IIf) with allyl derivatives of formula (VIII) in the presence of second generation Grubbs catalyst in a suitable solvent such as dry DCM at reflux overnight, such as 16 h.

When T2 denotes a —CO—CO—NH— group such as represented in Scheme 3, where W represents a single bond and Rw is as defined above, compounds of general formula (Id) may be prepared from compounds of formula (IIg) following conditions described above to convert compounds of formula (Ia) from compounds of formula (IIa) consisting of the oxidation of the secondary alcohol into a ketone followed by the acetonide deprotection. Compounds of formula (IIg) can be obtained from compounds of formula (IIb) by treatment with isocyanide derivatives of formula (IX) where Rw is as defined above. Preferred conditions consist of the treatment compounds of formula (II b) with chloroacetic acid and an isocyanide derivative of formula (IX) in a suitable solvent such as DCM at a temperature such as room temperature. The intermediate is then treated with a base such as K2CO3 in a MeOH:H2O mixture for several hours, such as 5 h, at a temperature such as RT.

Isocyanide of formula (IX) where Rw is as defined above can be obtained from compounds of formula (X) by treatment with ethylformate followed by the dehydration of the formamide intermediate as shown in Scheme 4. Preferred conditions consist of the treatment of amines of formula (X) with ethylformate at room temperature for a few hours, such as 12 h. The intermediate is then dehydrated by addition of trisphosgene in the presence of a base such as triethylamine in a suitable solvent such as DCM at a temperature such as 0° C. followed by an additional 30 min at RT.

As an alternative example, the compounds according to formula (Id) may be prepared following the synthetic pathway described in Scheme 5. According to a preferred synthetic pathway, compounds of formula (Id) may be prepared from the corresponding derivatives of formula (XIa), by an oxidation step followed by the cleavage of the acetal protecting group where W and Rw are as defined above. Preferred conditions consist of the treatment of compounds of formula (XIa) with an oxidant such as, but not limited to, Dess-Martin periodinane in a solvent such as dry DCM at room temperature for a few hours, such as 2 h, followed by treatment with preferably an 80% acetic acid solution in water at room temperature for several hours, such as 3 h. Compounds of formula (XIa) may be prepared from the corresponding acid derivatives of formula (XIb) by coupling with amine derivatives of formula (XII) wherein W and Rw are as defined above with W preferably representing a single bond. Starting from the acid (XIb), compounds of formula (XIa) can be obtained using usual conditions for the formation of an amide starting from a carboxylic acid and an amine by using coupling agents such as DCC, DIC, EDC, and HATU or via the formation of an acid chloride or an activated ester. Preferred conditions consist of the treatment of compounds of formula (XIb) with HATU in the presence of a base such as, but not limited to, N-methyl morpholine in a solvent such as DMF at a temperature such as 100° C. The corresponding carboxylic acid of formula (XIb) can be obtained by hydrolysis of the corresponding esters of formula (XIc) using reagents such as, but not limited to, LiOH, NaOH or KOH in solvents such water, alcohol, THF, dioxane, or a mixture thereof.
Compounds of formula (XIIIa) may be obtained either from commercial sources or following the procedure described in the journal Organic Letters, 2004, 6(26), 4801-4803.

Compounds of formula (Ie) where T2 is N(Ra)—CO—CH2— and Ra is as defined above can be obtained from compounds of formula (If) by treatment with chloroacetyl chloride followed by treatment with a base such as NaOH as shown in Scheme 6. Preferred conditions consist of the treatment of amines of formula (If) with chloroacetyl chloride in the presence of a base such as triethylamine in a suitable solvent such as dry DCM at a temperature such as 0° C. for an hour. The compound is then treated with a base such as a 10% aqueous solution of NaOH in a suitable solvent such as a THF:H2O mixture. Compounds of formula (If) where Ra is as defined above may be prepared from compounds of formula (Vb) following conditions described above to synthesize compounds of formula (IVa) from compounds of formula (VI) and amines of formula (Va) consisting of the opening of a pantolactone by an amine. Compounds of formula (Vb) can be obtained by treatment of compounds of formula (XV) with a sulfonyl chloride such as methane sulfonyl chloride followed by the reaction with ethylene diamine. Preferred conditions consist of the treatment of alcohol derivatives (XV) with methane sulfonyl chloride in the presence of a base such as, but not limited to, triethylamine in a suitable solvent such as dry DCM at a temperature such as 0° C. Methanesulfonic acid derivatives are then treated with ethylene diamine in a suitable solvent such as MeOH at a temperature such as RT for few hours, such as 16 h.
Experimental Part:
The compounds of invention have been named according to the standards used in the program AutoNom (v1.0.1.1).
The compounds according to formula (I) can be prepared from readily available starting materials by several synthetic approaches, using both solution-phase and solid-phase chemistry protocols or mixed solution- and solid-phase protocols. Examples of synthetic pathways are described below in the examples.